Prosthetic element comprising two components and process for assembling such a prosthetic element

Abstract

A prosthetic element comprising two principal components which are assembled together and immobilized with respect to each other by a screw which may be selectively threaded into at least one tapping in at least one of the principal components. The screw comprises at least one radial element adapted to abut against a stop surface within the first component, and a non-threaded end forming a guide which is adapted to slide in a bore in the second component.

1. A prosthetic element comprising first and second principal components, said first principal component including an outer articular surface (S), a threaded tapping within each of said first and second principal components, a screw for securing said first and second principal components together, said screw being provided with means including at least one threaded section for successively engaging said threaded tappings within said first and second components, said screw including at least one radial element which abuts against a stop within said first principal component and further including a non-threaded portion which extends from an end of said screw and towards said at least one threaded section thereof and which non threaded portion forms a guide and centering finger which is slidable in a bore in said second principal component so as to align said screw with said threaded tapping of said second principal component. 
     
     
       2. The prosthetic element of  claim 1 , wherein said at least one radial element is formed by a radial flange made between first and second threaded sections on said screw. 
     
     
       3. The prosthetic element of  claim 1 , wherein said stop is annular and surrounds said screw. 
     
     
       4. The prosthetic element of  claim 3 , wherein said stop is formed by a face of a bush screwed into another threaded tapping of said first principal component and said threaded tapping engageable by said at least one threaded section of said screw being formed in said bush. 
     
     
       5. The prosthetic element of  claim 1 , wherein said first principal component is provided with a recess defined by an annular side wall bearing surface, and said second principal component includes a plate having an outer annular wall defining a bearing surface for cooperatively engaging said side wall bearing surface of said recess as said at least one threaded section of said screw engages within said threaded tapping of said second component. 
     
     
       6. The prosthetic element of  claim 5 , wherein said bearing surfaces are respectively centered on a central axis of said screw and on a central axis of said bore. 
     
     
       7. The prosthetic element of  claim 1 , wherein said threaded tapping of said second component is formed in said bore. 
     
     
       8. The prosthetic element of  claim 1 , wherein said outer articular surface of said first principal component is convex and includes an internal recess in which said screw may be mounted and said second principal component at least partially engaged. 
     
     
       9. The prosthetic element of  claim 1 , wherein said bore for receiving said guide and centering finger is made in a shank for anchoring said second principal component in a bone. 
     
     
       10. A prosthetic element comprising first and second principal components, a threaded tapping within each of said first and second principal components, a screw for securing said first and second principal components together, said screw including at least one radial element which abuts against a stop within said first principal component and further including a non-threaded end portion forming a guide adapted to slide in a bore in said second principal component so as to align said screw within said bore and said screw being provided with first and second threaded sections which are spaced relative to one another so as to engage in a successive manner with said threaded tappings within said first and second principal components so that said first threaded section initially engages said threaded tapping within said first principal component after which said second threaded section engages said threaded tapping within said second principal component. 
     
     
       11. A prosthetic element comprising first and second principal components, a threaded tapping within each of said first and second principal components, a screw for securing said first and second principal components together, said screw including at least one radial element which abuts against a stop within said first principal component and further including a non-threaded end portion forming a guide adapted to slide in a bore in said second component so as to align said screw within said bore and said screw being provided with a threaded section adapted to engage, in a successive manner, with said threaded tappings within said first and second principal components. 
     
     
       12. Process for assembling a prosthetic element comprising two principal components and a screw, comprising the steps of:
 immobilizing said screw with respect to a first principal component by screwing said screw in a first threaded tapping within said first principal component; 
 sliding a bore of said second principal component over a free end of said screw which projects from said first principal component; 
 pushing said first and second principal components towards each other, causing said end of said screw to slide in said bore; 
 unscrewing said screw with respect to said first threaded tapping, and thereafter 
 
       screwing said screw in a second threaded tapping made in said second principal component to thereby secure said first and second principal components together. 
     
     
       13. Process for assembling of a prosthetic element comprising two principal components and a screw, comprising the steps of:
 immobilizing said screw with respect to a first principal component by screwing said screw in a first threaded tapping within said first principal component; 
 placing a bore of said second principal component over a free end of said screw which projects from said first principal component; 
 impacting one of said first and second principal components in a direction of the other so as to bring them closer, causing said free end to slide in said bore until said components are brought into contact with each other; 
 unscrewing said screw with respect to said first threaded tapping; and thereafter 
 screwing said screw in a second tapping made in said second principal component to secure said first and second principal components in contact with one another. 
 
     
     
       14. A prosthetic element for forming a part of a prosthesis, the prosthetic element comprising; a first component having an outer articular suface (S), a central recess, and first and second threaded tappings therein, a second component including a plate adapted to be at least partially cooperatively seated within said central recess and an anchoring shank having an internal bore, said second component having a threaded tapping therein aligned with said bore, a screw including at least one threaded section and an outwardly extending flange, said screw having a first non threaded end portion of a size to be guidingly received within said bore, a threaded annular bush selectively engageable with said first threaded tapping of said first component and serving as a stop to engage said flange of said screw to secure said screw within said first component, and said at least one threaded section of said screw being successively engageable with said second threaded tapping within said first component and said threaded tapping within said second component. 
     
     
       15. The prosthetic element of  claim 14  wherein an opening is provided through said outer articular surface (S) into said central recess through which a tool may be selectively inserted, and said screw having a second end portion configured to be cooperatively engaged by the tool. 
     
     
       16. The prosthetic element of  claim 15  wherein said second threaded tapping is formed within said opening to cooperatively receive said at least one threaded section of said screw. 
     
     
       17. The prosthetic element of  claim 14  wherein said screw includes first and second threaded sections that are separated by said flange, and said second threaded tapping within said first component and said threaded tapping within second component have threads extending in opposite directions. 
     
     
       18. A prosthetic element for forming a part of a prosthesis, the prosthetic element comprising; a first component having an outer articular suface (S), a central recess, and a first threaded tapping, a second component including a plate adapted to be at least partially cooperatively seated within said central recess and an anchoring shank having an internal bore, said second component having a threaded tapping aligned with said bore, a screw including at least one threaded section and an outwardly extending flange, said screw having a first non threaded end portion of a size to be guidingly received within said bore, said threaded tapping of said second component being threadingly engageable with said at least one threaded section of said screw, a threaded annular bush selectively engageable with said first threaded tapping of said first component and serving as a stop to engage said flange of said screw to secure said screw within said first component, and said threaded annular bush including a threaded tapping which is axially aligned with said threaded tapping of said second component and said at least one threaded section of said screw being successively threadingly engageable with said threaded tapping of said threaded annular bush that is secured within said first component and said threaded tapping within said second component. 
     
     
       19. The prosthetic element of  claim 18  wherein said screw includes a single threaded section extending between said flange and said non threaded end portion. 
     
     
       20. The prosthetic element of  claim 18  wherein an opening is provided through said outer articular surface (S) into said central recess through which a tool may be selectively inserted, and said screw having a second end portion configured to be cooperatively engaged by the tool.